For about the last 15 years, cognitive science has been embroiled in
a sometimes-bitter debate about the nature of mental representation.Very roughly speaking, the traditional view
is that cognitive processing is the serial manipulation of physical
"symbols," each of which locally represents a particular concept or
other unit of propositional attitudes.As a result, this position variously goes by the names of symbol(ic)ism, serialism,
and localism, among others.The newer
view is that cognition involves parallel computation over multiple
interconnected "nodes" that individually are semantically uninterpretable, but that collectively constitute
distributed mental representations.Such
networks go by the names of parallel distributed processing (PDP),
connectionism, and neural networks. In the mid-1980s, Patricia Churchland was one of the first philosophers to embrace
connectionist cognitive science, and it became closely connected with her Neurophilosophy (1986, MIT Press), which
essentially is the view that philosophers of mind should be keeping in much
closer contact with advances in the neurosciences if they hope to gain any real
insight into cognitive goings-on.

John Sutton's Philosophy and Memory
Traces: Descartes to Connectionism appears to be a kind of historical
defense of Churchlandian neurophilosophy,
particularly with respect to the theory of memory. The book is divided into
four major sections.The first, entitled
"Animal Spirits and memory traces," runs nearly 100 pp., and contains
two substantive chapters discussing the history of the theory of animal spirits.The first of these lays
in some conceptual background.The
second chapter develops an interpretation of Descartes' physiology of the brain
in which it is portrayed as a precursor to modern "distributed"
models of cognition.The second section,
"Inner discipline," consists of seven short
chapters, collectively about 100 pp., on various topics that follow what Sutton
describes as "the linked fates of animal spirits and of neurophilosophical
models of memory through the century after Descartes" (p.117).In the third section, "The phantasmal
chaos of association," about 50 pp., Sutton attempts to draw parallels
between Jerry Fodor's modern objections to connectionism and historical
critiques of associationism.Finally, in
the 50 pp. fourth section, the author attacks directly a number of
"standard" criticisms of distributed models of memory.

All this is preceded by a general introduction, outlining the
author's main aims.It appears to be straightforwardly
polemical.Sutton attempts to deploy
historical events in such a way as to establish the credibility of
neurophilosophy.It is said to have
first arisen in the writings of Descartes, but was distorted and suppressed
(see esp. pp. 10-11) by its opponents.Only now do we see its return, in the form of distributed connectionist
models of cognition, but back too are its old nemeses, hoping to drive it
underground once again.One can hardly
help but draw the conclusion that Sutton sees this as an epic struggle between
forces of light and darkness, but one in which the "Enlightenment"
tendencies toward "rationality" and "literality" are
(ironically?) cast in black hats, while "construction," "creativity,"
and a certain kind of exuberant "chaos" play to role of good guys. If this all sounds a little more postmodern
than typical discussions of cognitive science, it is.The introductory chapter is peppered with
references to "genealogy," "the body,"
"engagement," "context," "culture,"
"holism," "counter-theory," and the like.Sutton writes in a literary style, to be
sure: "Molly Bloom," he tells us at one point, "not Sherlock
Holmes, is the fictional figurehead for the neurophilosopher" (p.
17).

I see two key difficulties here.First, it is not at all clear how connectionism advances a postmodern or
neo-Wittgensteinian species of social philosophy any
more than traditional symbolic cognitive science does.Even Sutton concedes (p. 5) that the leading neurophilosophers have not had much to say about the
social, apart from a few motherhood clauses.Many connectionists are even more reductionistic than their symbolist
opponents -- even propositional attitudes are too "airy-fairy" for
them.Getting closer to the neural level
of description is the aim of most connectionists, not getting social about the
mind.Sutton's endorsement of
distributed memory models seems to stem from his belief that they "allow
for and invite such extensions [to social and ethical domains]" to a
greater degree than symbolic models.Second, his characterizations of symbolic memory models are so utterly one-sided
that we are hardly left even with straw men. Traditional theories are said to relegate
memory to "static records in cold storage" (p. 1), an "archive
caricature … [that] must be … lampooned" (p. 4), and "a dusty
corner" (p. 6).This kind of hyperbole
may have its place, but Sutton makes no attempt to seriously grapple with the
work of the best (if "localist") memory
researchers of the century: where are Miller, Broadbent, Milner, Baddeley, Craik, Squire, Tulving, etc.?They
are "erased" -- to borrow a term from Sutton's philosophical
tradition -- in favor of metaphor and allusion.

So, considered as quasi-historical intellectual polemic in the
service of contemporary neurophilosophy, how does the rest of the book shape
up? Chapter 2 is an interesting but impossibly short romp through the semantic
cross-currents of the theory of "animal spirits" prior to
Descartes.Relying almost entirely upon
secondary sources, Sutton touches on the theological, biological, occult,
medical, and moral connotations of "spirit" in pre-modern
centuries.Sutton's stated aim is not to
revive sprit theory, per se, but rather to show that its multifarious semantics
may tell us something important about the way we should conceive of memory today.

Having "softened up" his readers for new
perspectives on old, rejected accounts of mind, Sutton attempts in Chapter 3 to
reclaim Descartes from present-day rationalists (e.g., Fodor, Chomsky) by
re-interpreting his speculative brain physiology as a precursor to present-day
distributed models of memory.Sutton repeatedly attempts to distance
himself from the anachronistic implications of such a project, but this is
difficult to countenance.The chapter
only makes sense as an attempt at "discipline building" by
appropriating an authoritative historical figure to the side of neurophilosophy.But
still, the chapter should not be dismissed.Sutton has important points to make, and his attempt to make sense of
Descartes' physiology is welcomeSutton also carefully outlines
pre-emptive replies to the most obvious criticisms of his interpretation.There can be little doubt, however, that the
motivation at work is more about rhetorical strategy than about gaining insight
into Descartes' thought.

The second section of the book highlights English responses to
Descartes' memory theory.Chapter 4
parallels the "realism" of 17th-century mechanists with
that of modern connectionists such as Paul Churchland
(p. 123).Sutton says the two positions
"chime well," but one cannot help but warily notice that their
respective opponents -- "Aristotelian scholastics" and anti-realists
such as Van Fraassen, respectively -- have little in
common.Sutton also suggests that Robert
Hooke's interest in superposition and interference
patterns in the physics of light may have influenced his position on memory.Chapter 5 briefly examines that the reactions
of four Englishmen -- Hooke, KenelmDigby, JospehGlanvill, and Henry More -- to the Cartesian theory of
memory, with the aim of demonstrating that Descartes' advocacy of distributed
representation, rather than his dualism, was the main target of their
objections.There are some interesting details
here, but the chapter is unhappily short.In Chapter 6, Sutton steps back from his historical narrative to clarify
two distinctions on which his argument depends: local vs. distributed mental representation
and implicit vs. explicit mental representation.The second of these, in particular, has provoked
enormous debate in psychology, not just with respect to connectionist models of
cognition, but with respect to memory and learning more generally.Many believe the distinction to be
fundamentally incoherent. Sutton does not seem to recognize the connection of his
specific issue to the these more general debates, and the
import of his comments suffer accordingly.In Chapter 7 he seems to argue that even Locke was "moving
towards" a distributed view of memory (and the person), but this view turns
on the questionable identification of Locke's description of memories being
"revived" ideas with the modern belief that memories are
"reconstructed" (p. 168).In
the end, Sutton waters his claim down to one in which Locke's own model is
admitted to have been "localist," but that
he was "aware, too, of the other [memory] phenomena which a distributed
model takes seriously" (p. 173). Chapter 8 briefly explores the reasons
that spirit theory continued to be popular, even after 17th-century
experiments showed that muscles do not increase in volume when contracted (and
thus could not have been infused with additional "spirit").Despite some interesting historical material,
the analysis seems to be tainted with Sutton's implicit expectation that
scientists -- even of the 17th and 18th centuries --
would feel honor-bound to abide by strict Popperianfalsificationism.Naturally enough, they did not, and alternative interpretations of the
experiments allowed "spirits" to live another day.The moral implications of spirit theory,
which constitute an increasingly significant theme in the early chapters, are
brought to a head in Chapter 9, which traces the 18th-century
"crisis" in spirit theory that arose from the full realization of its
irrationalist implications.Not just the free and rational will, but also
the forces of disease, distemper, weakness -- even the Devil -- were thought to
affect the distribution of spirits, causing all manner of erroneous perception,
belief, memory, and action.The
implication seems to be that this threat to Enlightenment ideals did more to
drive spirit theory from scientific respectability than any empirical findings
or theoretical innovations, but Sutton refrains from asserting this definitively,
preferring instead to "consider" five alternative hypotheses about
its decline in chapter 10.

Section III opens with a short chapter (11) on Jerry Fodor's
criticisms of connectionist cognitive science.Interestingly, the main target of the Sutton's attack is not Fodor's
philosophy of mind, but his philosophy of science, which Sutton surprisingly
suggests parallels 18th- and 19th-century moral critiques of associationism.In Chapter 12, he tries to show that
criticisms of classical associationism do not bear against
"neo-associationism" (i.e., connectionism) because, as he puts it at
one point, "nothings [e.g., ideas, neurons] are associated at all in distributed
models" (p. 243).This is supposed
to be an advantage, but the reader not committed to connectionism in advance is
left wondering what, exactly, such models model if not "things" of
any sort.What relation, exactly do the
nodes and connections of the networks bear to "natural" cognition?Chapter 13 examines the relation of Hartley's
vibrational theory of memory to modern distributed
networks, but, as is typical of the book, does so extremely breifly.
The final chapter (14) of the section critically skims through Reid's and
Coleridge's efforts to refute Hartley and his associationist colleagues.

In the fourth and final section of the book, Sutton shifts from the
historical to the contemporary -- "clearing the ground …. by showing that distributed models … do not suffer the
conceptual incoherence with which critics charge them" (p. 277).Chapter 15 attempts to employ distributed
models of memory to "dissolve" the dispute between "direct
realism" (à la J.J. Gibson) and representationalism.The effort is somewhat quixotic, as Gibsonians represent a tiny minority of perceptionists,
and virtually no memory researchers.Nor
does Gibson appear much in the connectionist literature, though Sutton keenly points
up some exceptions.Gibson is presented
as a figure who can let Sutton have his neo-Wittgensteinian
cake and eat it too (i.e., reject the "storage" memory theory in
favor of a "social," "dynamic" but still
"scientific" theory). Chapter 16 rehearses several standard
criticisms of "trace" memory theories, and argues that distributed
models -- particularly "unsupervised" connectionist networks -- do
not fall victim to them.In the final
chapter (17), Sutton makes a plea for accepting the "chaos" of memory
processes rather than "imposing" an artificial
"rationalist" order upon them.

Many aspects of this book -- especially the chapters on Descartes
and Locke -- are interesting. In the
end, however, I found it unconvincing.I
wonder exactly which constituency Sutton was writing for.Those from the "localist"
tradition are likely to regard it as a transparent attempt to extract
historical authority for connectionism from tendentious re-interpretations of
past eminent philosophers.The connectionist
community might be less critical because he's on their "side," but
Sutton's sometimes-florid style and Wittgensteinian sensibilities
will not resonate well there.Finally, Wittgensteinian critics of all attempts at cognitive science
are not likely to be convinced by Sutton's efforts to set connectionism apart
from other modes of "objective" mental modeling.Connectionism does little to address either the
normative issues involved, or the (correct) impression that, in the final analysis,
connectionist network are every bit
as mechanistic as the localist, symbolic models they
aspire to displace.